Process for treating keratin fibres with an oxidised polysaccharide and a sphingosine compound

ABSTRACT

The invention relates to a process for treating keratin fibres, in particular human keratin fibres such as the hair, comprising: •(i) a step of applying an oxidized polysaccharide, •(ii) a step of heating to a temperature of at least 100° C., •(iii) a step of applying a compound (I) •Ri—CHOH—CH(NH—COY)(CH2OH) (I). The invention also relates to a cosmetic composition comprising an oxidized polysaccharide and a compound (I) for which Y═H and to kits. The process makes it possible to obtain good hair-conditioning cosmetic properties, with a long-lasting effect.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a national stage application of PCT/EP2014/069377, filed internationally on Sep. 11, 2014, which claims priority to French Application No. 1358760, filed on Sep. 12, 2013, both of which are incorporated by reference herein in their entireties.

The invention relates to a cosmetic process for treating keratin fibres, in particular human keratin fibres such as the hair, using an oxidized polysaccharide combined with sphingosine-based compound.

Hair is generally damaged and embrittled by the action of external atmospheric agents such as light, sunlight and bad weather, and also by mechanical or chemical treatments, such as brushing, combing, dyeing, bleaching, permanent-waving, relaxing and repeated washing. Hair is thus damaged by these various factors and may in the long run become dry, coarse, brittle or dull or split or limp.

Thus, to overcome these drawbacks, it is common practice to resort to hair treatments which use compositions intended for conditioning the hair appropriately by giving it satisfactory cosmetic properties, especially a soft feel (the hair is no longer coarse), good disentangling properties leading to easy combing, and good manageability of the hair which is thus easy to shape.

These haircare compositions may be, for example, conditioning shampoos, hair conditioners, masks or sera.

However, the conditioning effect obtained fades out in the course of successive shampoo washes and does not show satisfactory persistence on shampooing.

In the field of dyeing, patent application FR 2 944 967 discloses the use of oxidized polysaccharides for protecting the colour of keratin fibres that have been artificially dyed, especially by oxidation dyeing or direct dyeing.

There is thus a need for a process for treating keratin fibres, in particular the hair, that is capable of durably conditioning the keratin fibres, the conditioning effect being persistent after one or more shampoo washes performed on the treated keratin fibres.

The Applicant has discovered that the application to keratin fibres, in particular the hair, of oxidized polysaccharide and of sphingosine derivative as defined below followed by a heating step makes it possible to obtain good hair-conditioning cosmetic properties, with a durable effect over time, especially after one or more shampoo washes.

Thus, one subject of the invention is a process for treating keratin fibres, in particular the hair, comprising:

(i) a step of applying to the keratin fibres at least one oxidized polysaccharide;

(ii) a step of heating the keratin fibres to a temperature of at least 100° C., preferably ranging from 100 to 250° C.,

(iii) a step consisting in applying to the said fibres one or more sphingosine derivatives of formula (I) defined below.

The treatment process according to the invention makes it possible to obtain good keratin fibre-conditioning cosmetic properties.

In particular, hair treated via the process according to the invention has a softer feel and remains managed since no presence of frizziness is observed. Thus, the hairs are aligned, smooth and disentangle easily, which makes them easier to comb. The treated hair also has more body (it is not limp) and is thus easier to style. Moreover, the treated hair is also shinier. It is stronger and less brittle.

After treatment, the hair is not lank, and has a natural feel.

The process according to the invention has the advantage of giving good persistence of these good hair-conditioning cosmetic properties after shampooing. Thus, the treated hair is durably conditioned.

The process according to the invention also has the advantage of not bringing about a change in the colour of the treated hair.

The oxidized polysaccharide(s) used in the process according to the invention are preferably anionic or nonionic polysaccharides.

The anionic or nonionic oxidized polysaccharides consist of monosaccharide units that may comprise five or more carbon atoms, preferably six or more carbon atoms, and more particularly six carbon atoms.

The nonionic or anionic oxidized polysaccharides comprise one or more aldehyde groups and optionally one or more anionic groups.

These anionic groups are preferably carboxyl or carboxylate groups.

The anionic or nonionic oxidized polysaccharides according to the invention may be represented by formula (II) below: P—(CHO)_(m)(COOX)_(n)  (II)

in which:

P represents a polysaccharide chain consisting of monosaccharides comprising 5 carbon atoms or more than 5 carbon atoms, preferably 6 or more than 6 carbon atoms and more particularly 6 carbon atoms;

X is chosen from a hydrogen atom, the ions derived from an alkali metal or an alkaline-earth metal such as sodium or potassium, ammonia, organic amines such as monoethanolamine, diethanolamine, triethanolamine and 3-amino-1,2-propanediol and basic amino acids such as lysine, arginine, sarcosine, ornithine and citrulline,

m+n is greater than or equal to 1,

m is such that the degree of substitution of the polysaccharide with one or more aldehyde groups (DS(CHO)) is within the range from 0.001 to 2 and preferably from 0.005 to 1.5,

n is such that the degree of substitution of the polysaccharide with one or more carboxylic groups (DS(COOX)) is within the range from 0 to 2 and preferably from 0.001 to 1.5.

The term “degree of substitution DS(CHO) or DS (COOX) of the polysaccharides according to the invention” means the ratio between the number of carbons oxidized as an aldehyde or carboxylic group for all the repeating units and the number of elemental monosaccharides (even opened by preoxidation) constituting the polysaccharide.

The groups CHO and COOX may be obtained during the oxidation of certain carbon atoms, for example in position C₂, C₃ or C₆, of a saccharide unit comprising 6 carbon atoms. Preferably, the oxidation may take place at C₂ and at C₃, more particularly from 0.01% to 75% by number and preferably from 0.1% to 50% by number of the rings having possibly been opened.

The polysaccharide chain, represented by P, is preferably chosen from inulins, celluloses, starches, guar gums, xanthan gums, pullulan gums, alginate gums, agar-agar gums, carrageenan gums, gellan gums, gum arabics, xyloses and tragacanth gums, and derivatives thereof, cellobiose, maltodextrin, scleroglucan, chitosan, ulvan, fucoidan, alginate, pectin, heparin and hyaluronic acid, or mixtures thereof.

More preferentially, the polysaccharide chain is chosen from inulins and starches.

Even more preferentially, the polysaccharide chain is inulin.

The term “derivative” means the compounds obtained by chemical modification of the mentioned compounds. They may be esters, amides or ethers of the said compounds.

The oxidation may take place according to a process known in the art, for example according to the process described in FR 2 842 200, in document FR 2 854 161 or in the article “Hydrophobic films from maize bran hemicelluloses” by E. Fredon et al., Carbohydrate Polymers 49, 2002, pages 1 to 12. Another oxidation process is described in the article “Water-soluble oxidized starches by peroxide reaction extrusion” Industrial Crops and Products 75 (1997) 45-52—R. E. Wing, J. L. Willet. These oxidation processes are easy to perform, are efficient and do not generate any toxic by-products or by-products that are difficult to remove.

The peroxides that may be used in these oxidation processes may be an alkali metal or alkaline-earth metal percarbonate or perborate, an alkyl peroxide, peracetic acid or hydrogen peroxide. Hydrogen peroxide is particularly preferred, insofar as it is readily accessible and does not produce interfering by-products.

The amount of peroxide in the reaction medium is between 0.05 and 1 molar equivalent per glucose unit of the polysaccharide, preferably between 0.1 and 0.8 molar equivalent. It is preferable to add the peroxide in successive portions, leaving the reaction medium stirring between two additions.

A single phthalocyanin or a mixture of phthalocyanins, for example a mixture of cobalt phthalocyanin and of iron phthalocyanin, may be used as catalyst in the oxidation process. The amount of catalyst depends on the desired degree of substitution. In general, a small amount, for example an amount corresponding to 0.003 to 0.016 molar equivalent per 100 glucose units of polysaccharide, is suitable for use.

The process may also be performed by placing the polysaccharide in pulverulent form in contact with the catalyst dissolved in a small volume of water and with the peroxide. This process is referred to as a “semi-dry” process.

The process may be performed by reactive extrusion in the presence of peroxide.

More preferentially, the polysaccharide is obtained by oxidation of inulin, cellulose, carboxymethylcellulose, hydroxyethyl cellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, starch, starch acetate, hydroxyethyl starch, hydroxypropyl starch, guar gum, carboxymethyl guar gum, carboxymethylhydroxypropyl guar gum, hydroxyethyl guar gum, hydroxypropyl guar gum, xylose, xanthan gum or carrageenan gum, cellobiose, maltodextrin, scleroglucan, chitosan, ulvan, fucoidan, alginate, pectin, heparin and hyaluronic acid, or mixtures thereof.

Preferentially, the polysaccharide is obtained by oxidation of inulin or starch.

Preferentially, the polysaccharide is obtained by oxidation of inulin.

According to one embodiment, the polysaccharide is obtained by oxidation of inulin by performing a reactive extrusion process in the presence of hydrogen peroxide.

The polysaccharide chain before and after oxidation preferably has a weight-average molecular mass ranging from 400 to 15 000 000, better still from 500 to 10 000 000 and more particularly from 500 to 50 000 g/mol.

The polysaccharides that are most particularly preferred in the invention are those corresponding to formula (II) in which: P represents a polymer chain derived from inulin or from starch, m is such that the degree of substitution of the polysaccharide with one or more aldehyde groups (DS(CHO)) is within the range from 0.005 to 2.5, n is such that the degree of substitution of the polysaccharide with one or more carboxylic groups (DS(COOX)) is within the range from 0.001 to 2.

Even more preferably, P represents a polymer chain derived from inulin, m is such that the degree of substitution of the polysaccharide with one or more aldehyde groups (DS(CHO)) is within the range from 0.01 to 1, n is such that the degree of substitution of the polysaccharide with one or more carboxylic groups (DS(COOX)) is within the range from 0.01 to 2.

Advantageously, the step of applying the oxidized polysaccharide consists in applying a cosmetic composition comprising the oxidized polysaccharide especially in a content ranging from 0.05% to 15% by weight, preferably ranging from 0.1% to 10% by weight and more preferentially ranging from 0.2% to 6% by weight relative to the total weight of the composition.

The sphingosine derivative used in the process according to the invention is a compound of formula (I) below: R₁—CHOH—CH(NH—COY)(CH₂OH)  (I)

in which R₁ denotes a C₁₁ to C₂₁ hydrocarbon-based radical, Y denotes H or R₂, R₂ denoting a linear, optionally hydroxylated C₁₁-C₁₉ hydrocarbon-based radical and the hydroxyl group being alpha to the carbonyl, and possibly comprising one or more ethylenic unsaturations, especially one or two ethylenic unsaturations.

For the compounds of formula (I), preferably, R₁ denotes a C₁₃-C₁₉ hydrocarbon-based radical; Y denotes H or R₂, R₂ denoting a linear, optionally hydroxylated C₁₃-C₁₉ hydrocarbon-based radical, which may comprise one or more ethylenic unsaturations.

Preferentially, R₁ denotes a C₁₃-C₁₇ hydrocarbon-based radical; y denotes H or R₂, R₂ denoting a linear, optionally hydroxylated C₁₃-C₁₉ hydrocarbon-based radical, which may comprise one or more ethylenic unsaturations.

Advantageously, R₁ denotes a C₁₃-C₁₇ hydrocarbon-based radical; Y denotes H or R₂, R₂ denoting either a linear C₁₃-C₁₉ hydrocarbon-based radical which may comprise one or more ethylenic unsaturations, or a hydroxylated linear C₁₃-C₁₉ saturated hydrocarbon-based radical, the hydroxyl group being alpha to the carbonyl.

The hydrocarbon-based radical R₁ may be saturated or unsaturated.

According to one embodiment of the invention, a compound (I) for which Y═H is used.

According to another embodiment of the invention, a compound (I) for which Y═R₂ as defined previously is used.

As particularly preferred compounds of formula (I), use may be made of dihydrosphingosine, N-oleoyldihydrosphingosine and N-2-hydroxypalmitoyl-dihydrosphingosine.

The compounds of formula (I) are known from the prior art, especially in patent applications EP-A-500 437 and EP-A-647 617.

Advantageously, the step of applying the compound (I) consists in applying a cosmetic composition comprising the compound (I) especially in a content ranging from 0.001% to 5% by weight, preferably ranging from 0.002% to 3% by weight and preferentially ranging from 0.005% to 2% by weight relative to the total weight of the composition. Advantageously, compound (I) is present in the cosmetic composition containing it in a content ranging from 0.01% to 5% by weight, preferably ranging from 0.02% to 3% by weight and preferentially ranging from 0.05% to 2% by weight relative to the total weight of the composition.

According to one embodiment of the process according to the invention, the oxidized polysaccharide and the compound (I) are present in separate cosmetic compositions. They are therefore applied separately to the keratin fibres.

According to another embodiment of the process according to the invention, the oxidized polysaccharide and the compound (I) are present in the same cosmetic composition. They are therefore applied simultaneously to the keratin fibres.

A subject of the invention is also a composition comprising, in a physiologically acceptable medium, an oxidized polysaccharide as defined previously and a compound of formula (I) as described previously in which R₁ denotes a C₁₁ to C₂₁ alkyl radical and X denotes H. Preferably, the composition comprises a physiologically acceptable aqueous medium.

A subject of the invention is also a kit comprising:

a first cosmetic composition comprising an oxidized polysaccharide and a second cosmetic composition comprising a compound (I), the first and second compositions each being packaged in a separate packaging assembly,

the polysaccharide being as defined previously,

compound (I) having the formula as described previously in which R₁ denotes a C₁₁ to C₂₁ alkyl radical and Y denotes H.

A subject of the invention is also a kit comprising:

either a cosmetic composition comprising an oxidized polysaccharide and a compound (I), the composition being contained in a packaging assembly, or a first cosmetic composition comprising an oxidized polysaccharide and a second cosmetic composition comprising a compound (I), the first and second compositions each being packaged in a separate packaging assembly,

the polysaccharide being as defined previously,

compound (I) having the formula as described previously in which R₁ denotes a C₁₁ to C₂₁ alkyl radical and Y denotes H;

and a device for heating keratin fibres to a temperature of at least 100° C., preferably ranging from 100 to 250° C., such as those described below.

The composition packaging assembly is, in a known manner, any packaging that is suitable for storing cosmetic compositions (bottles, tube, spray bottle or aerosol bottle especially).

Such a kit makes it possible to perform the keratin fibre treatment process according to the invention.

The cosmetic compositions used according to the invention contain a physiologically acceptable medium, i.e. a medium that is compatible with human keratin materials such as the skin (of the body, face, around the eyes or the scalp), the hair, the eyelashes, the eyebrows, bodily hair, the nails or the lips.

The physiologically acceptable medium of the composition(s) used in the process according to the invention is advantageously an aqueous medium. It may consist, for example, of water or of a mixture of water and of at least one cosmetically acceptable organic solvent. Examples of organic solvents that may be mentioned include C₂-C₄ lower alcohols, such as ethanol and isopropanol; polyols, especially those containing from 2 to 6 carbon atoms, for instance glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, dipropylene glycol or diethylene glycol; polyol ethers, for instance 2-butoxyethanol, propylene glycol monomethyl ether and diethylene glycol monomethyl ether or monoethyl ether; and mixtures thereof.

Preferably, the cosmetic composition comprises from 50% to 99.5% by weight of water relative to the weight of the composition.

The composition used according to the invention may also contain one or more cosmetic additives chosen from nonionic, anionic, cationic and amphoteric surfactants, vitamins and provitamins, including panthenol, sunscreens, fillers, dyestuffs, nacreous agents, opacifiers, sequestrants, film-forming polymers, plasticizers, thickeners, oils, antioxidants, antifoams, moisturizers, emollients, penetrants, fragrances and preserving agents.

The composition used according to the invention may be in any galenical form conventionally used for application to the hair and especially in the form of aqueous solutions, aqueous-alcoholic solutions, oil-in-water (O/W), water-in-oil (W/O) or multiple (triple: W/O/W or O/W/O) emulsions, aqueous gels or aqueous-alcoholic gels. These compositions are prepared according to the usual methods. Preferably, the composition is in the form of an aqueous or aqueous-alcoholic solution or gel.

The process according to the invention comprises a step of heating the keratin fibres to a temperature of at least 100° C., preferably ranging from 100 to 250° C. Preferably, the step of heating the keratin fibres is performed at a temperature ranging from 150 to 220° C., preferably ranging from 160° C. to 220° C., preferentially ranging from 160° C. to 200° C. and especially ranging from 170° C. to 190° C.

This heating step is advantageously performed using an iron.

The heating step is necessary to optimize the effects of the process.

For the purposes of the present invention, the term “iron” means a device for heating keratin fibres by placing the said fibres and the heating device in contact.

The end of the iron which comes into contact with the keratin fibres generally has two flat surfaces. These two surfaces may be made of metal or ceramic. In particular, these two surfaces may be smooth or crimped or curved.

The heating step may be performed by means of a straightening iron, a curling iron, a crimping iron or a steam iron. Preferably, the heating step is performed using a straightening iron.

As examples of irons that may be used in the straightening process according to the invention, mention may be made of any type of flat iron, and in particular, in a nonlimiting manner, those described in patents U.S. Pat. Nos. 5,957,140 and 5,046,516. The iron may be applied by successive separate strokes lasting a few seconds or by gradual movement or sliding along the locks of keratin fibres, especially of hair. Preferably, the iron is applied in the process according to the invention by a continuous movement from the root to the end of the hair, in one or more passes, in particular in two to twenty passes. The duration of each pass of the iron may last from 2 seconds to 1 minute.

Preferably, the step of heating the keratin fibres is performed for a time that may range from 2 seconds to 30 minutes, preferentially from 2 seconds to 20 minutes, better still from 2 seconds to 10 minutes, better still from 2 seconds to 5 minutes and even better still from 2 seconds to 2 minutes.

The process according to the invention may also comprise an additional step of drying the keratin fibres after the application of the oxidized polysaccharide and/or of the compound (I) or of the cosmetic composition(s) containing the same and before the step of heating the keratin fibres performed at a temperature of at least 100° C. The drying step may be performed using a hairdryer or a hood or by open drying. The drying step is advantageously performed at a temperature ranging from 20 to 70° C.

After the drying step, the keratin fibres may be optionally rinsed with water or washed with a shampoo. The keratin fibres are then optionally dried using a hairdryer or a hood or in the open air.

According to one embodiment, the process according to the invention is performed on natural keratin fibres, especially natural hair.

According to another embodiment, the process according to the invention is performed on keratin fibres, especially hair, which are not artificially dyed.

For the purposes of the present invention, the term “keratin fibres that are not artificially dyed” means keratin fibres that have not been dyed following a direct dyeing process or via an oxidation dyeing process.

According to another embodiment, the process according to the invention is performed on damaged keratin fibres, especially hair. As indicated previously, the term “damaged hair” means dry or coarse or brittle or split or limp hair.

In particular, the treatment process according to the invention may be performed on damaged keratin fibres that are not artificially dyed.

In other words, the treatment process according to the invention is preferably performed on sensitized keratin fibres, especially hair, especially fibres which are not artificially dyed, such as bleached, relaxed or permanent-waved fibres.

According to one embodiment, when the process uses a compound of formula (I) for which Y is not hydrogen, the process is performed on keratin fibres, especially hair, that is not artificially dyed.

The process according to the invention may be performed on keratin fibres, especially hair, which is dry or wet. Preferentially, the process is performed on dry keratin fibres, especially dry hair.

After application to the keratin fibres of the oxidized polysaccharide and/or of the compound (I), or of a cosmetic composition containing the same, and before performing the step of heating the keratin fibres, the oxidized polysaccharide and/or the compound (I) or the composition(s) containing the same may be applied for a time ranging from 1 to 60 minutes, preferably ranging from 2 to 50 minutes and preferentially ranging from 5 to 45 minutes. The composition may be left on at a temperature ranging from 15° C. to 45° C., preferably at room temperature (25° C.).

The cosmetic composition(s) described previously are advantageously applied to the keratin fibres in an amount ranging from 0.1 to 10 grams and preferably from 0.2 to 5 grams of composition per gram of keratin fibres.

After application of the cosmetic composition to the keratin fibres, they may be manually dried to remove the excess composition or washed with water or with a shampoo.

According to a first embodiment of the process according to the invention, the following steps are performed, in the following order: the step of applying the oxidized polysaccharide, then the step of applying the compound (I) and then the heating step. Advantageously, the polysaccharide is present in a first cosmetic composition and the compound (I) is present in a second cosmetic composition. This second composition is separate from the first composition.

According to a second embodiment of the process according to the invention, the following steps are performed, in the following order: simultaneously, the step of applying the oxidized polysaccharide and the step of applying the compound (I) and then the heating step. Advantageously, the oxidized polysaccharide and the compound (I) are present in a single cosmetic composition.

According to a third embodiment of the process according to the invention, the following steps are performed, in the following order: the step of applying the oxidized polysaccharide, then the heating step, then the step of applying the compound (I) and then optionally an additional heating step.

The treatment process according to the invention may be performed before, during and/or after an additional process of cosmetic treatment of the keratin fibres, such as a process for temporarily shaping (shaping with curlers, a crimping iron or a straightening iron) or a process for durably shaping (permanent-waving or relaxing) the keratin fibres.

The treatment process may be performed as a pre-treatment to a dyeing or relaxing process and/or a permanent-waving process so as to cosmetically protect the keratin fibres against these treatments. In other words, this process is performed to preserve the cosmetic properties of the keratin fibres before a cosmetic treatment process as described previously.

The treatment process according to the invention may also be performed as a post-treatment to a cosmetic treatment process, especially not leading towards artificially dyeing the keratin fibres.

In particular, the treatment process is performed as a post-treatment to a bleaching or relaxing process and/or a permanent-waving process so as to repair the said fibres.

The process according to the invention may be performed during a cosmetic treatment process, especially not leading towards artificially dyeing the keratin fibres, so as to repair the said fibres.

In particular, the treatment process according to the invention may be performed on damaged keratin fibres that are not artificially dyed.

In other words, the treatment process according to the invention is preferably performed on sensitized keratin fibres, especially fibres that are not artificially dyed, such as bleached, relaxed or permanent-waved fibres.

In particular, the treatment process may be performed before a dyeing or relaxing process and/or a permanent-waving process on keratin fibres.

As a variant, the treatment process may be performed during and/or after a cosmetic treatment process not leading to the artificial dyeing of keratin fibres, in particular:

-   -   (a) during and/or after a process of permanent-waving or a         process of relaxing keratin fibres, and     -   (b) after a process of bleaching keratin fibres.

Preferably, the treatment process is performed during a cosmetic treatment process not leading to the artificial dyeing of keratin fibres.

According to one embodiment, the treatment process according to the invention is performed after a process of bleaching the keratin fibres.

The examples that follow are given as illustrations of the present invention. The amounts indicated in the examples are expressed as weight percentages.

Oxidized Polysaccharide Tested (Compound 1)

Compound 1 was prepared by oxidation of inulin sold under the name Inutec N25 by the company Orafti, by performing a reactive extrusion process as described in the article “Water-soluble oxidized starches by peroxide reactive extrusion” by R. E. Wing and J. L. Willett, Industrial Crops and Products 7, 1997, pages 45-52. A BC21 co-rotating twin-screw extruder sold by the company Clextral was used, and aqueous hydrogen peroxide solution was used as oxidizing agent.

Compound 1: oxidized inulin obtained by reactive extrusion of a mixture of 78% by weight of inulin and 1.57% by weight of aqueous hydrogen peroxide solution; the spontaneous pH after reactive extrusion is 3.8. Compound 1 thus obtained has a carbonyl content of 1.23% (w/w) and a carboxyl content of 0.17% (w/w).

Compositions Prepared

Compositions A B C D E X Compound 1 1 1 1 N- 0.1 1 Oleoyldihydrosphingosine Dihydrosphingosine 1 1 Water/ethanol — qs (50/50 100 weight/weight) Water/ethanol qs qs (70/30 100 100 weight/weight) Water qs qs qs 100 100 100

In the application examples described below, locks of hair that were highly sensitized after bleaching (SA 45%) were used. The composition to be evaluated is applied at a rate of 10 g of composition per gram of locks. Each composition tested is applied on three locks.

Application Process 1:

Composition A (containing 1% of compound 1) was applied to locks of hair and then left on for 15 or 30 minutes at 40° C.

The locks were dried manually and composition B (containing 0.1% of N-oleoyl-dihydrosphingosine) or composition E (containing 1% of dihydrosphingosine) was then applied and left on for 15 minutes at 40° C., and the locks were then dried manually again.

The locks were then dried under a hood for 10 minutes at 60° C.

The locks were combed before applying a straightening iron at a temperature of 180° C. by performing five continuous passes through the locks for 40 seconds.

For comparative purposes, the same protocol was also performed on locks with on the one hand, composition A (1% of compound 1) and, on the other hand, composition B and composition E. A control lock treated only with water and with or without application of the straightening iron was also prepared.

To evaluate the durable (persistent) nature of the cosmetic properties of the locks of hair, they were then washed with one shampoo according to the following protocol:

The treated locks were washed with an aqueous solution containing 15% by weight of sodium lauryl ether sulfate at a rate of 0.4 g of shampoo per gram of hair, at a temperature of 38° C.

Moisten the lock for 5 seconds with water. Apply the shampoo, massaging the lock from the root to the end for 15 seconds. Rinse with water for 10 seconds. Dry manually. Dry the locks for 10 minutes per gram of hair at 60° C. with a hairdryer.

The cosmetic properties of the locks after shampooing was then evaluated, especially the cosmetic feel, the manageability and the ease of combing of the locks, the body effect and the sheen.

The following results were obtained:

Type of lock of hair Cosmetic properties after shampooing Sensitized hair treated with Coarse feel. Dull lock and difficult to comb. composition (X) (control) (Lock 1) Sensitized hair treated with Less coarse feel. Difficult to comb, same composition (X) (control) + heat (Lock 2) level as Lock 1. Dull Lock. Sensitized hair treated with Slightly manageable lock, easier to comb composition (A) + heat (Lock 3) than Lock 1. The hair has body. Slightly improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable composition (B) + heat (Lock 4) and soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable composition (E) + heat (Lock 11) and soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock very easy to comb, manageable and composition (A) and then very soft feel. The hair has the most body. composition (B) + heat (Lock 5) Markedly improved sheen. Sensitized hair treated with Lock very easy to comb, manageable and composition (A) and then very soft feel. The hair has the most body. composition (E) + heat (Lock 6) Markedly improved sheen.

The locks of hair were then classified as a function of their cosmetic properties (soft, pleasant cosmetic feel, manageability, ease of combing, sheen and hair body) after having performed one shampoo wash.

After shampooing Lock 5 ≈ Lock 6 > Lock 4 > Lock 11 > Lock 3 > Lock 2 > Lock 1

The locks treated via the process according to the invention, and after having undergone one shampoo wash, have better cosmetic properties in terms of soft feel, manageability and ease of combing, and the hair has more body and markedly improved sheen. These cosmetic properties thus have good persistence on shampooing.

In addition, the colour of the treated hair is not modified.

Application Process 2:

Composition C (containing 1% of compound 1 and 1% of N-oleoyl-dihydrosphingosine) and composition D (containing 1% of compound 1 and 1% of dihydrosphingosine) were independently applied to locks of hair, for 30 minutes at 40° C.

The locks were dried manually and then dried under a hood for 10 minutes at 60° C.

The locks were combed before applying a straightening iron at a temperature of 180° C. by performing five continuous passes through the locks for 40 seconds.

For comparative purposes, the same protocol was also performed on locks with, on the one hand, composition A (1% of compound 1) and, on the other hand, composition B and composition E. A control lock treated only with water and with or without application of the straightening iron was also prepared.

To evaluate the durable (persistent) nature of the cosmetic properties of the locks of hair, they were then washed with a shampoo according to the protocol described previously.

The following results were obtained:

Type of lock of hair Cosmetic properties after shampooing Sensitized hair treated with Coarse feel. Dull lock and difficult to comb. composition (X) (control) (Lock 1) Sensitized hair treated with Less coarse feel. composition (X) (control) + heat Difficult to comb, same level as Lock 1. Dull lock. (Lock 2) Sensitized hair treated with Slightly manageable lock, easier to comb than composition (A) + heat (Lock 3) Lock 1. The hair has body. Improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable and composition (B) + heat (Lock 4) soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable and composition (E) + heat (Lock 11) soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock very easy to comb, manageable and very composition (C) + heat (Lock 7) soft feel. The hair has the most body. Markedly improved sheen. Sensitized hair treated with Lock very easy to comb, manageable and very composition (D) + heat (Lock 8) soft feel. The hair has the most body. Markedly improved sheen.

The locks of hair were then classified as a function of their cosmetic properties (soft, pleasant cosmetic feel, manageability, ease of combing, sheen and hair body) after having been shampooed.

After shampooing Lock 8 > Lock 7 > Lock 4 >> Lock 11 > Lock 3 > Lock 2 > Lock 1

Locks 7 and 8 treated via the process according to the invention, and after having undergone a shampoo wash has better cosmetic properties in terms of soft feel, manageability and ease of combing, and the hair has more body and markedly improved sheen. These cosmetic properties thus have good persistence on shampooing.

In addition, the colour of the treated hair is not modified.

Application Process 3:

Composition A (containing 1% of compound 1) was applied to locks of hair, for 15 minutes at 40° C.

The locks were dried manually and then dried under a hood for 10 minutes at 60° C.

The locks were combed before applying a straightening iron at a temperature of 180° C. by performing five continuous passes through the locks for 40 seconds. Composition B (containing 0.1% of N-oleoyldihydrosphingosine) was then applied for 15 minutes at 40° C., or composition E (containing 1% of dihydrosphingosine) was applied for 30 minutes at 40° C.

The locks were dried manually and then dried under a hood for 10 minutes at 60° C.

For the locks of hair treated with composition E, the locks were combed before applying a straightening iron at a temperature of 180° C. by performing five continuous passes through the locks for 40 seconds.

For comparative purposes, the same protocol was also performed on locks with, on the one hand, composition A (1% of compound 1) and, on the other hand, composition B and composition E. A control lock treated only with water and with or without application of the straightening iron was also prepared.

To evaluate the durable (persistent) nature of the cosmetic properties of the locks of hair, they were then washed with a shampoo according to the protocol described previously.

The following results were obtained:

Type of lock of hair Cosmetic properties after shampooing Sensitized hair treated with Coarse feel Dull lock and difficult to comb. composition (X) (control) (Lock 1) Sensitized hair treated with Less coarse feel. composition (X) (control) + heat Difficult to comb, same level as Lock 1. Dull lock. (Lock 2) Sensitized hair treated with Slightly manageable lock, easier to comb than composition (A) + heat (Lock 3) Lock 1. The hair has body. Improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable and composition (B) + heat (Lock 4) soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock easy to comb, sparingly manageable and composition (E) + heat (Lock 11) soft, pleasant cosmetic feel. The hair has no body. Improved sheen. Sensitized hair treated with Lock very easy to comb, manageable and very composition (A) + heat and then soft feel. The hair has the most body. Markedly with composition (B) + heat (Lock improved sheen. 9) Sensitized hair treated with Lock very easy to comb, manageable and very composition (A) + heat and then soft feel. The hair has the most body. Markedly with composition (E) (Lock 10) improved sheen.

The locks of hair were then classified as a function of their cosmetic properties (soft, pleasant cosmetic feel, manageability, ease of combing, sheen and hair body) after having been shampooed.

After shampooing Lock 9 ≈ Lock 10 > Lock 4 > Lock 11 > Lock 3 > Lock 2 > Lock 1

Locks 9 and 10 treated via the process according to the invention, and after having undergone a shampoo wash has better cosmetic properties in terms of soft feel, manageability and ease of combing, and the hair has more body (good styling effect) and markedly improved sheen. These cosmetic properties thus have good persistence on shampooing.

In addition, the colour of the treated hair is not modified. 

The invention claimed is:
 1. A process for treating damaged keratin fibers, the process comprising: (i) applying to the keratin fibers a cosmetic composition comprising at least one oxidized polysaccharide in an amount ranging from about 0.2% to about 6% by weight, relative to the total weight of the composition, wherein the at least one oxidized polysaccharide is chosen from those of formula (II): P(CHO)m(COOX)n  (II) wherein: P is a polysaccharide chain chosen from inulins, X is chosen from a hydrogen atom, ions derived from an alkali metal or an alkaline-earth metal, sodium ion, potassium ion, ammonia, organic amines, monoethanolamine, diethanolamine, triethanolamine, 3-amino-1,2-propanediol, basic amino acids, lysine, arginine, sarcosine, ornithine, or citrulline, m+n is greater than or equal to 1, m is such that the degree of substitution of the polysaccharide with at least one aldehyde group (DS(CHO)) ranges from about 0.001 to about 2, and n is such that the degree of substitution of the polysaccharide with at least one carboxylic group (DS(COOX)) ranges from about 0 to about 2, (ii) heating the keratin fibers at a temperature of at least about 170° C., and (iii) applying to the keratin fibers at least one sphingosine derivative compound chosen from dihydrosphingosine, N-oleoyldihydrosphingosine, or N-2-hydroxypalmitoyldihydrosphingosine.
 2. The process according to claim 1, wherein the at least one oxidized polysaccharide is anionic or nonionic.
 3. The process according to claim 1, wherein the at least one oxidized polysaccharide comprises at least one aldehyde group and optionally at least one anionic group, carboxyl group, and/or carboxylate group.
 4. The process according to claim 1, wherein applying the at least one sphingosine derivative compound comprises applying a cosmetic composition comprising the sphingosine derivative compound in an amount ranging from about 0.001% to about 5% by weight, relative to the total weight of the cosmetic composition.
 5. The process according to claim 1, wherein the heating step is performed at a temperature ranging from about 170° C. to about 250° C.
 6. The process according to claim 1, wherein the steps are performed in a sequence chosen from the following: applying the at least one oxidized polysaccharide or a first cosmetic composition comprising the at least one oxidized polysaccharide, then applying the at least one sphingosine derivative compound or a second cosmetic composition containing the at least one sphingosine derivative compound, and then heating the keratin fibers; simultaneously applying the at least one oxidized polysaccharide or a first cosmetic composition comprising the at least one oxidized polysaccharide, and the at least one sphingosine derivative compound or a second cosmetic composition comprising the at least one sphingosine derivative compound, and then heating the keratin fibers; applying a cosmetic composition comprising both the at least one oxidized polysaccharide and the at least one sphingosine derivative compound, and then heating the keratin fibers; or applying the at least one oxidized polysaccharide or a first cosmetic composition comprising the at least one oxidized polysaccharide, then heating the keratin fibers, then applying the at least one sphingosine derivative compound or a second cosmetic composition comprising the at least one sphingosine derivative compound, and then optionally heating the keratin fibers an additional time.
 7. The process according to claim 1, wherein the process further comprises drying the keratin fibers after the application of the at least one oxidized polysaccharide and/or of the at least one sphingosine derivative compound and before heating the keratin fibers, the drying step being performed at a temperature ranging from about 20° C. to about 70° C.
 8. The process according to claim 1, wherein after application to the keratin fibers of the at least one oxidized polysaccharide and/or of the at least one sphingosine derivative compound, and before heating the keratin fibers, the at least one oxidized polysaccharide and/or the at least one sphingosine derivative compound is left on the keratin fibers for a time ranging from about 1 to about 60 minutes.
 9. The process according to claim 1, wherein the heating step is performed with a straightening iron.
 10. The process according to claim 1, wherein the heating step is performed by applying a straightening iron to the keratin fibers in a substantially continuous movement from the root to the end of the keratin fibers, in at least one pass.
 11. The process according to claim 1, wherein the process is performed on damaged keratin fibers, keratin fibers that are not artificially dyed, and/or hair.
 12. The process according to claim 1, wherein either or both of the at least one oxidized polysaccharide and/or the at least one sphingosine derivative compound is present in a cosmetic composition comprising a physiologically acceptable aqueous medium. 